► Folded flap covers, made of light gray acid-free cardboard, with neutral pH, with 240grs / m2 or 330grs / m2, for the storage of sets of documents or books.
 ► Acid-free cardboard, without wood, pH between 8.0 - 9.0, oxidation resistance between 1-2, calcium carbonate reserve greater than 4%, smooth surface.
 ► Available in the following sizes: A4 (305x215mm); A5 (215x155mm); Folio (345x220mm); Folio L (365x250mm); A3 (425x305mm)
 ► Sold in packs of 50 or 100 units.